Environmental drivers of taste characteristics in wild edible plants: Effects of topographic gradients and human harvesting evaluated using dwarf bamboo culms

Wild edible plants grow in natural environments with little direct human management; consequently, their productivity and quality frequently exhibit pronounced spatiotemporal variability, making stable supply difficult. This variability represents a major constraint on the exploitation of wild edible plants as local food resources, and overcoming it requires an ecological understanding of the factors affecting variation in both productivity and quality. Here, we examined the effects of human harvesting and environmental factors on the taste characteristics of young culms of Sasa kurilensis. No statistically significant differences were detected between harvested and control plots in any major taste index, including umami, bitter aftertaste, astringency, umami richness, and sweetness (measured as Brix values). In contrast, taste characteristics showed substantial variation among study plots, suggesting a strong association with local environmental conditions. Elevation and slope angle were significantly correlated with bitter aftertaste, umami, and sweetness; plots at higher elevations and on steeper slopes tended to produce plants with a less bitter aftertaste, and higher sweetness and umami. Principal component analysis integrating multiple taste indices revealed that the major axis of taste variation was significantly associated with elevation, and that harvesting treatment had no detectable effect. These results suggest that the taste characteristics of young culms in the study area are governed primarily by topographic gradients rather than by human harvesting. Although wild edible plants are important food resources in boreal and temperate forests worldwide, many are poorly managed. By quantitatively establishing relationships between taste characteristics and environmental factors in young culms, this study provides a scientific basis for determining the optimal timing, location, and selection criteria for wild edible plant harvesting, thereby contributing to the development of sustainable use strategies.